some facts in case you are wondering:
-Multiplayer will be available in around 5h from the posting of this comment
-Changelog is here: Median-xl.com
-If you're interested, here you can download the official launcher: Get.median-xl.com
-If you're experiencing some errors with the mod read here for possible solutions: Forum.median-xl.com

It probably means that you've been using Glide-Wrapper but its .dll got erased by something or blocked by some software. Try to download this package: Svenswrapper.de and once unzipped drag its content in your D2 installation folder